Eur. Phys. J. D 40, 297-303 (2006)
https://doi.org/10.1140/epjd/e2006-00149-4

Quantum memory process with a four-level atomic ensemble

¹ Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, P.R. China
² Theoretical Physics Division, Nankai Institute of Mathematics, Nankai University, Tianjin, 300071, P.R. China
³ Liuhui Center for Applied Mathematics, Nankai University and Tianjin University, Tianjin, 300071, P.R. China
⁴ State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, CAS, Wuhan, 430071, P.R. China

Corresponding author: ^a phylx@nus.edu.sg

Received: 12 January 2006
Revised: 19 April 2006
Published online: 28 June 2006

Abstract

We examine in detail the quantum memory technique for photons in a double Λ atomic ensemble in this work. The novel application of the present technique to create two different quantum probe fields as well as entangled states of them is proposed. A larger zero-degeneracy class besides dark-state subspace is investigated and the adiabatic condition is confirmed in the present model. We extend the single-mode quantum memory technique to the case with multi-mode probe fields, and reveal the exact pulse matching phenomenon between two quantized pulses in the present system.